smtp - Unable to send mail to a email server -

i using phpmailer library send email through mail server domain name pixels.com .i able send emails email addresses gmail, yahoo etc.,but unable send mail email addresses belongs same server admin@pixels.com.can suggest me solution problem .do need change setting.what other possible solutions solve issue.my php code sending mail is

 <?php     require("class.phpmailer.php");      $mail = new phpmailer();  $mail->issmtp();                                      // set mailer use      smtp $mail->host = "smtp1.example.com;smtp2.example.com";  // specify main , backup server $mail->smtpauth = true;     // turn on smtp authentication $mail->username = "jswan";  // smtp username $mail->password = "secret"; // smtp password  $mail->from = "from@example.com";   $mail->fromname = "mailer";   $mail->addaddress("josh@example.net", "josh adams");    $mail->addaddress("ellen@example.com");                  // name optional     $mail->addreplyto("info@example.com", "information");       $mail->wordwrap = 50;                                 // set word wrap 50 characters            $mail->addattachment("/var/tmp/file.tar.gz");         // add attachments          $mail->addattachment("/tmp/image.jpg", "new.jpg");    // optional name          $mail->ishtml(true);                                  // set email format html         $mail->subject = "here subject";       $mail->body    = "this html message body <b>in bold!</b>";      $mail->altbody = "this body in plain text non-html mail clients";    if(!$mail->send())      {    echo "message not sent. <p>";    echo "mailer error: " . $mail->errorinfo;     exit;     }  echo "message has been sent";      ?> 

you should update phpmailer version using, code work in old versions, try exploring github page, have lot of examples there.